Process for the disposal of combustible refuses

Abstract

The invention relates to a process for the disposal of combustible refuses in the manufacture of cement clinker by preheating and partly calcining the cement raw meal in a preheater, burning in a rotary kiln and subsequently air cooling the clinker, the refuse being separately burned and the flue gas obtained thereby transfers its heat to the cement raw meal. In the process according to the invention, hot exhaust air of the clinker cooler is fed to the refuse incineration and flue gas having a temperature of from 1000° to 1400° C. is produced during said incineration by means of which the cement raw meal is calcined. The slag of the refuse incineration is separately discharged.

We claim: 
     
       1. In the disposal of combustible refuse and the manufacture of cement clinker from cement raw meal by a process comprising the steps of (a) preheating and calcining the cement raw material in a preheater,   (b) feeding the preheated calcined cement raw material produced in (a) into a cement rotary kiln,   (c) burning the calcined raw material in the rotary kiln to form clinker, and subsequently air cooling said clinker in a clinker cooler, thereby producing hot exhaust air, and   (d) incinerating the combustible refuse in an incinerator generating flue gas and slag, and transferring heat from the flue gas to the cement raw material, the improvement which comprises     (i) feeding hot exhaust air from (c) to the incinerator in (d),   (ii) conducting the incineration in (d) to produce flue gas of 1000°-1400° C. and feeding it to (a), and   (iii) separating the slag produced in (d).   
     
     
       2. A process according to claim 1, wherein the flue gas produced in (d) has a temperature of from 1150° to 1400° C. 
     
     
       3. A process according to claim 1, wherein the exhaust air from the clinker cooling in (c), withdrawn for the refuse incineration, has a temperature of from 300° to 800° C. 
     
     
       4. A process according to claim 1, wherein the refuse incineration in (d) takes place in a rotary kiln. 
     
     
       5. A process according to claim 1, wherein the refuse is incinerated in (d) without previous processing. 
     
     
       6. A process according to claim 1, wherein the exhaust gas produced in the cement clinker rotary kiln in (c) is at least partly cooled and dedusted and at least part of the dust is removed from the system. 
     
     
       7. A process according to claim 6, wherein part of the exhaust gas produced in the cement clinker rotary kiln in (c) is utilized for drying cement raw meal or additives for cement manufacture, or for calcining cement raw meal. 
     
     
       8. A process according to claim 1, wherein the slag from the refuse incineration in (d) is discharged as molten flow into a water bath. 
     
     
       9. A process according to claim 1, wherein the slag produced in the refuse incineration in (d) is ground together with Portland cement clinker and gypsum for the manufacture of cement. 
     
     
       10. A process according to claim 1, wherein part of the exhaust gas produced in the cement clinker rotary kiln in (c) is used for predrying the refuse. 
     
     
       11. A process according to claim 1, wherein part of the exhaust gas produced in the cement clinker rotary kiln in (c) is utilized for indirectly heating up air of combustion for the refuse incineration in (d). 
     
     
       12. A process according to claim 1, wherein part of the gas stream through the preheater or leaving the preheater or part of the material streams passing the preheater or being collected at the exhaust gas dust collector following the preheater in direction of the gas flow in (a) is branched off and conveyed to the cement clinker rotary kiln in (c). 
     
     
       13. A process according to claim 1, wherein part of the flue gas leaving the preheater in (a) is joined with exhaust gas of the cement clinker rotary kiln in (c) and is jointly cooled and dedusted together therewith. 
     
     
       14. A process according to claim 1, wherein the burning in the cement clinker rotary kiln in (c) is conducted by supplying oxygen or oxygen enriched air to said kiln. 
     
     
       15. A process according to claim 1, wherein the incineration of the refuse in (d) is conducted by supplying oxygen or oxygen enriched air to the incinerator. 
     
     
       16. A process according to claim 1, wherein heat at a temperature below 800° C. is indirectly drawn from the gas previously used for calcining in (a). 
     
     
       17. A process according to claim 1, wherein water is sprayed into the gas used for calcining in (a) which is at a temperature between 400° C. and 800° C.